Ocean Temperature UPSC NOTE

Why in News

Ocean temperatures hit a record high in February.
With the average global sea surface temperature at 21.06 degrees Celsius (69.91 degrees Fahrenheit).
The EU’s Copernicus Climate Change Service (C3S) said on March 7.
February’s average sea surface temperature surpassed the previous record of 20.98°C (69.77°F) set in August 2023, in a dataset that goes back to 1979.

Alarming rise in ocean temperatures and its consequences

The oceans are absorbing a massive amount of heat, and the consequences are dire.

Here's a breakdown of this alarming trend:

The Reality: Our oceans are experiencing record-breaking temperatures.
February 2024 saw the hottest average global sea surface temperature ever recorded, surpassing the previous record set just months before.
This relentless warming trend is attributed to greenhouse gas emissions and climate change.
The Culprit: The primary culprit behind rising

ocean temperatures is greenhouse gas emissions, particularly carbon dioxide, which trap heat in the atmosphere.

The oceans act like a giant heat sink, absorbing much of this excess heat.
The Consequences: The effects of a warming ocean are widespread and far-reaching:

Marine Life Disruption: Coral reefs, vital marine ecosystems, bleach and die due to rising temperatures.
Fish populations are forced to migrate to cooler waters, disrupting food chains and fisheries.

Extreme Weather Events: Warmer oceans fuel more powerful storms and hurricanes.
Increased evaporation leads to heavier precipitation in some areas and exacerbates droughts in others.
Sea Level Rise: As oceans warm, they expand, causing sea levels to rise.
This threatens coastal communities with flooding and erosion.
Ocean Acidification: Oceans absorb some of the excess carbon dioxide, becoming more acidic.
This harms marine life with calcium carbonate shells and skeletons, like shellfish and coral.

The Ripple Effect: The consequences of rising ocean temperatures extend far beyond marine life.
They impact food security, coastal economies, and weather patterns worldwide.
The Need for Action: Urgent action is required to curb greenhouse gas emissions and mitigate climate change.
This includes transitioning to renewable energy sources, reducing dependence on fossil fuels, and implementing sustainable practices.

Impact on Coral Reefs

Coral Bleaching: This is the most immediate and visible consequence.
Corals have a symbiotic relationship with algae called zooxanthellae.
These algae live within the coral tissues and provide them with nutrients through photosynthesis.
However, rising water temperatures stress the coral, causing them to expel the zooxanthellae, which drains their color and leaves them pale or white - hence the term "coral bleaching.“
Bleached corals are more susceptible to disease and death.

Reduced Growth and Calcification: Warmer water slows down the growth rate of corals and disrupts their ability to build their calcium carbonate skeletons.
This weakens reefs and makes them more vulnerable to damage from waves, storms, and erosion.
Shifts in Coral Distribution: As temperatures rise, some coral species may migrate to cooler waters in search of suitable conditions.
This can disrupt entire ecosystems and put stress on the corals as they adapt to new environments.

Loss of Biodiversity: Coral reefs are incredibly diverse ecosystems, teeming with marine life.
When coral reAefs decline, it has a domino effect on the entire food chain.
Fish populations dwindle, and the vibrant underwater world loses its complexity.

Causes of temperature rise in ocean